Snatch-block.



V. E. THOR?.

SNATCH BLOCK.

APPLlcA'TloN FILED ocT. 21

Eatented A111113, 1915.

INVENTORZ @WZ 34%.

HAMON, D4 C* W m vu n W w U n r s m T s P b n R o N E H T iur ad VERNOR E. THORP, OF ALAMEDA, CALIFORNIA.

SNATCI-I-BLOCK.

Application led October 21, 1911.

To all whom t may concern: f

Be it known that I, VERNOR EDWIN THORP, a citizen of the United States7 residing in the city and county of Alameda and State of California, have invented a new and useful Improvement in Snatch- Blocks, of which the following is a speelcation.

My invention relates to automatic release snatch-blocks.

In using cables or ropes to haul objects 1t is necessary to use a snatch-block wherever it is desired to change the direction of the pull. Heretofore it has been necessary in such hauling to stop the power, slacken the rope and throw it out of the block by hand, then start the load in the new direction.

The objects of my invention are to provide means for automatically releasing the rope when the load has reached the turn, to arrange a release mechanism that will safelv hold the block closed, yet be easily tripped, together with a minimum amount of wear on the catch.

With these and other objects in view my invention consists in certain novel features of construction and arrangements of parts hereinafter more fully described, reference being had to the accompanying drawings in which- Figure 1 is a view of the hinge side of my newly invented snatch-block. Fig. 2 is a view of the reverse side showing the release mechanism closed. Fig. 8 is a vertical section on line A B of Fig. 1. Fig. 4 shows the block open. Fig. 5 shows the rope buttons for releasing the trip mechanism.

Similar numerals refer to similar parts throughout the several views.

The aXle A carrying the sheave B is mounted in the frame members 2 and 3. The members 3, 4 and 5 form a double hinge on one side of the block, the member 2 on the other side is provided with the keeper lu 6.

:(Ietween the forks of the member 7 is mounted the trip lever 8 carrying the toggle pawl 9. The members 2 and 3 are riveted together at the bottom by the eyelet 10, and the upper members by the rivets 11 and 12, thus making a four part frame easy of construction and cheaply put together. The cross-head being formed by the separate frame members 5 and 7 make it a simple matter to insert the swivel hook 14, which may be forged and headed complete Specification of Letters Patent.

Patented Apr. 13, 1915.

serial No. 655,905.

before being set in the block. 'Ihe protection disks 15 16 are riveted to the frame members 2 and 8. The pawl 9 is pivoted to the trip lever 8 which is pivoted at 17 between the forks of the member 7, the trip lever is provided with the trip lug 18 and the eye 19.

The trip buttons on the hauling cable 2O consist of hollow hard metal shells 21 22 set on the cable by pouring in the soft metal 28. It is obvious that when the row of buttons on the cable reach the sheave they should bend to t the contour thereof, for

this reason I use several short buttons so as to get their combined grip on the cable and prevent them from slipping.

In operation, the rope is put into the open block Fig. 4 which is then closed and locked as in Fig. 3 with the rope 20 in the sheave groove. As the load approaches the block the button 21 being larger than the rope will engage the lug 18, this will kick the lug up and to the left bringing the pin 25 out of line with the keeper lug 6 and the pin 17, the pressure of the keeper lug 6 on the end of the pawl 9 will throw the lever 8 still farther out until the lug 26 engages the stop 27, the rope will then throw the block entirely open, the keeper lug 6 meanwhile following the dotted lines Fig. 4.

It is obvious that with only one hinge located as at 28, the rope leverage on the sheave would be too small to open the sheave without considerable erosion of the rope on the edges of the sheave, and again if a single hinge were located as at 29 the keeper lug 6 would describe an arc reaching out into and beyond the lever 8 and prevent the sheave from opening. To obviate these difficulties I use the double hinge 28 29 which allow the rope to throw out gently and with a minimum amount of wear on the edges of the sheave.

In some cases, such as aboard ship, it is not convenient to use the buttons, it being necessary to release the rope at different points, for this purpose I provide the lever and eye 19 whereby the block may be tripped with the hand at any time. However, for purely automatic purposes the hand portion of the lever may be omitted.

It will be readily seen that the arrangement of the toggle catch will obviate the wear on catch and keeper lug as there is no slippage in the contact. With the toggle pawl and lever the block frame is forcibly locked together, the shoulders 31 being pressed tightly together, with a minimum amount of pressure on the lever and as easily opened, yetwhile in the locked position no amount of strain on the rope can i throw the lever.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is- 1. In a snatch-block, the combination with an axle and sheave of a hand looking and automatic releasing mechanism, comprising a frame hinged on one side and adapted to open on the opposite side, the upper portion of said open side having downwardly projecting forks, a lever pivotally-jointed between said forks at the lower end and bent at the upper end to project within the frame, a pawl toggle-jointed to said lever and arranged to engage a keeper lug on the lower abutting portion of said open side, said Ymechanism adapted to automatically open lthe block, with a buckling non-sliding movement of the locking parts, by projections on the rope while said rope is traveling under strain.

i 2. In a snatch-block, the lcombination with an aXle and sheave of a hand locking and lreleasing mechanism, comprising a frame hinged on one side and adapted to open on the opposite side, the upper portion of said open side having downwardly projecting forks, a lever fulcrumed between said forks, a pawl toggle-jointed to said lever and arranged to engage a keeper lug on the lower abutting portion of said open side, said mechanism adapted to be hand operated to open the block with a buckling and nonsliding movement of the locking parts and while the rope isunder strain.

3. In a snatch-block, the combination with a hinged frame, an axle and sheave, of a hand locking and hand and automatic releasing mechanism, comprising a hand lever having a trip lug forming an integral part thereof, said lever being fulcrumed between downwardly projecting forks of the upper frame portion, a pawl toggle-jointed to the lever and arranged to engage a keeper lug on the lower abutting frame portion, said mechanism adapted to hold the frame in a locked position, and to release automatically by means of projections on the rope or by hand, without sliding of the locking parts.

VERNOR E. TI-IORP. Witnesses J. M. THoRP, DOROTHY M. THORP.

Copies of this patent may be obtained for ve cents each, 'by addressing the Commissioner' of Patents, Washington, D. O. 

